How to use the %% operator in R

This operator is from the magrittr package and it is for you to pass an object to a function at the same time by modifying the object you passed.

For example, suppose the following x in text format:

library(magrittr)    
x <- "1"

Suppose you want to convert this x to numeric. One way to do this is to assign x to the result of the as.numeric function on itself:

x <- as.numeric(x)

With %<>% you do the same thing without having to type x twice, because the %<>% operator passes x to as.numeric and then rewrites x :

x %<>% as.numeric # mesma coisa de x <- x %>% as.numeric

That is, while <- modifies only the left-hand variable with the right expression, %<>% modifies the left-hand variable after passing this variable to a function that is on the right.

In the background this is a syntax question, such as %>% .